A semiconductor wafer container that is widely and generally used has a container body with an opening for loading and unloading a plurality of semiconductor wafers, a cover externally removably attached to the opening to close the opening, wafer retaining means for retaining the plurality of semiconductor wafers individually and independently in the container body, and a front retainer disposed at the back side of the cover to elastically press the semiconductor wafers from the opening side toward the innermost side of the container body.
It should be noted that a semiconductor wafer may be damaged by the wafer retaining means, retainer or the like if the latter comes in plane contact with the semiconductor wafer. Therefore, the wafer retaining means, retainer or the like has a V-groove shaped cross-sectional configuration at a semiconductor wafer retaining portion thereof so as to contact only the ridges of the outer edge of a semiconductor wafer.
The structures of the wafer retaining means for retaining semiconductor wafers in such semiconductor wafer containers are roughly divided into two types. In the first type, V-groove shaped wafer retaining grooves (or rear retainer) are disposed on the inner surface of the innermost (as seen from the opening) part of the container body to retain semiconductor wafers therein by elastic pressing force applied from the front retainer provided on the cover.
In this regard, however, guide grooves are formed in rows on the inner surfaces of side walls of the container body at the opposite ends of the opening under the need of orderly guiding each semiconductor wafer inserted into the container body from the opening toward the innermost side of the container body.
The guide grooves need not have a V-shaped cross-sectional configuration. The semiconductor wafers come out of engagement with the guide grooves when clamped from the front and rear sides between the front retainer of V-shaped cross-sectional configuration and the V-groove shaped wafer retaining grooves (or rear retainer) (for example, Patent Literature 1).
In the second type of semiconductor wafer containers, V-groove shaped wafer retaining grooves are provided in rows and in mutually opposing pairs on the inner surfaces of side walls of the container body that are located at the opposite ends of the opening.
With this type, the wafer retaining grooves, which are provided on the side walls, per se are formed with wafer movement restraining portions that restrain inward movement of the semiconductor wafers so that the semiconductor wafers will not reach the innermost wall of the container body (for example, the distance between each pair of mutually opposing wafer retaining grooves is reduced at the innermost side thereof). At the innermost position in the container body, the outer edges of the semiconductor wafers are floating in the space without contacting the wall surface or the like of the container body (for example, Patent Literature 2).
Citation List
Patent Literatures
Patent Literature 1: Japanese Patent Application Publication No. 2002-9142 FIG. 8 and so forth
Patent Literature 2: Japanese Patent Application Publication No. 2000-68363